Hybrid Vehicles: High Voltage Circuit Disconnect Overview

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Hybrid Vehicles High Voltage Circuit Disconnect
Overview
Special Thanks to Mr. Tom Melito of Heyward Allen
Toyota in Athens, Ga for his help in preparing
this lesson written by Whitney Kizer.

• Whitney Kizer
• and
• Dr. Frank B. Flanders

Georgia CTAE Resource Network Curriculum Office
July 2008
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CAUTION!!!
These procedures are for GENERAL KNOWLEDGE ONLY!
The following steps and procedures are only to be
performed by qualified technicians.
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High Voltage CircuitWHAT??

• The high voltage circuit disconnect or SERVICE
  PLUG on a hybrid vehicle connects the large
  battery to the rest of the car. Without the
  service plug the car could not run.
• Service plugs are small, plastic pieces the fit
  into the side of the battery in a hybrid.

Service Plug
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The Service Plug Does What?

• The service plug connects all the electricity
  within a hybrid.
• When you remove the service plug from the main
  battery it stops the flow of electricity through
  the car.
• The service plug must be removed BEFORE any
  electrical service can be done on the car.

Service plug
Main LARGE battery.
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Location of the Hybrid Vehicle Service Plug

• The hybrid vehicle service plug is generally
  located underneath/behind the BACK SEAT of the
  car.
• To complete electrical service on a hybrid
  vehicle the backseat must be removed to get to
  the service plug.

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Use Caution When Servicing Hybrid Batteries and
Electrical Systems

• High-voltage wire harness connectors are colored
  ORANGE and also are usually accompanied by High
  Voltage caution labels.
• Technicians have to be careful to follow special
  safety precautions when dealing with hybrid
  inspections and servicing.

Electrical circuitry within a hybrid engine.
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Safety Precautions Continued

• Technicians should wear insulated gloves and
  remove the service plug to prevent ELECTROCUTION.
• Technicians should carry the service plug in your
  pocket to prevent other technicians reinstalling
  the service plug while work is being done on the
  hybrid vehicle.

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Servicing Safety Continued

• After removing the service plug, wait 5 minutes
  prior to beginning work to discharge the
  high-voltage condenser inside the inverter.
• Use CAUTION HIGH VOLTAGE. DO NOT TOUCH DURING
  OPERATION signs to notify other technicians of
  service being conducted on the hybrid vehicle.

Gasoline Engine
Electric Motor
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General Safety Procedures

• Before wearing insulated gloves, check to make
  sure they are not cracked or have holes or are
  damaged in any other way.
• Do not carry metal objects when servicing the
  vehicle. Dropping these items could cause a SHORT
  CIRCUIT within the vehicle.

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Lets Review

• The high-voltage service plug helps CONNECT the
  electrical components of a hybrid vehicle.
• The safety plug is a component of the BATTERY.
• SAFETY is of the utmost importance when servicing
  a hybrid vehicle.

• INSULATED GLOVES should be used to protect the
  technician from being ELECTROCUTED.
• Hybrid electrical components are easily
  distinguished from other wiring because they have
  ORANGE WIRES.

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That, That, That, Thats All Folks!!!